Home intrusions are one of the most frightening crimes that can occur to a person. The sense of violation of personal space and the terror of knowing that a stranger was in one's living space makes this type of crime far more upsetting than the simple loss of property caused by many other crimes. In addition, many “home” intrusions occur in hotel rooms, dorm rooms and other temporary living spaces where the occupant does not have control of the type of locks and other security devices.
Below follows a summary of related art.
U.S. Pat. No. 4,358,758 (1982) to Morton discloses a door jam that extends as well as an electric switch which senses a closure of the jam tube, thereby activating an electronic alarm. The device does not have a cam extension tube, but rather a crude multi-hole and clip length adjustment.
U.S. Pat. No. 4,442,427 (1984) to Morton adds a smoke alarm to his '758 patent.
U.S. Pat. No. 4,607,253 (1986) to Wooten et al. discloses a door jam with pads at each end and a switch to sense a movement of the shaft.
U.S. Pat. No. 5,131,701 (1992) to Stepniewski discloses a door jam having a cam actuated extension tube to create a wedge effect against the door.
U.S. Pat. No. 5,333,922 (1994) to Jones discloses a segmented door jam with a non-skid pad on the foot.
U.S. Pat. No. 5,340,175 (1994) to Wood discloses a door jam with a switch to sense an attempted door opening, an interchangeable carpet/hard floor foot and a length adjuster.
U.S. Pat. No. 5,392,026 (1995) to Marik discloses a door jam with a motion detector.
U.S. Pat. No. 5,787,548 (1998) to Tzen discloses a door jam with a cam/handle activated extension tube.
The above inventions have several limitations. Most are not easy for the user to transport from one location to another, making them unsuitable for use by travelers. Jones '922 discloses a segmented door jam that can be taken apart and folded into a portable form. However, the segments of Jones are not attached together in any way when they are taken apart, so it is possible for segments to get lost or left behind, rendering the device useless. In addition, it takes time for the user to assemble and disassemble the device. Most of the above inventions also only have one footpad surface to rest on the floor, making them difficult or impossible to use on a variety of surfaces.
Most of the above do not have a motion sensor. Those that do have a motion sensor have the motion sensor on the shaft of the device, instead of at the yoke, reducing the potential sensitivity of the motion sensor. Since part of the purpose of an audible alarm is to scare away a potential intruder, it is advantageous to have the potential to detect someone trying the doorknob and/or trying to pick the lock. In addition, most of the present inventions do not have any type of visual alarm, making it less useful for hearing impaired users.